Exception: System.NullReferenceException Message: Object reference not set to an instance of an object
This error mean you use default host header of site core instead of host header pf your sxa site To solve your problem:
- Browse using your SXA Host Header Url.
- Check Solr Cores exist sitecore_sxa_matser_index,; sitecore_sxa_web_index. If not exist create them using the following Command: solr create_core -c new_core -d basic_configs
- Polulate schema and rebuild index.